Steam generator



Patented June 1, 1926.

LAWRENCE E. CONNELLY, 0F CLEVELAND HEIGHTS, OHIO.

STEAM GENERATOR.

Application filed February'21, 1925. Serial No. 10,883.

This invention relates to steam generators, of the class known as the cross-drum and bent tube type.

The object'ot this invention is to provide a water tube steam generator having a plurality of lower and upper transverse drums connect-ed by banks of tubes all enclosed in a setting in such a manner that the volume of the furnace gas passing among the banks of tubes proportionately decreases as the gas cools on its way to the damper controlled outlet to the chimney, and to eliminate baffle walls and the consequent sharp return bends of tire' gas, and thereby provide a direct draft thus making tall chimneys and forced draft fans unnecessary.

Another object of my invention is to permit an arrangement of banks of water tubes transverse of the course of the current of fire gas so that they will themselves act as baffles through which the fire gas will percolate andv thus retard the speed thereof.

Another object of this invention is to provide feed-water preheating apparatus within the boiler setting, whereby feed-water is introduced into the apparatus at the point within the setting where the fire gas is coolest.

These and other` features of my invention will appear hereinafter and are illustrated in the drawing, in which:

The figure is a vertical section of a steam boiler embodying my invention.

In this drawing A indicates the'lower or mud-drum, and B indicates the steam liberating drum, said drums being connected by a bank of upflow water tubes C, and a bank of downilow watertubes /fthe banks of upfiow tubes C and down-flow tubes C being spaced apart, and in the space thus provided, I place steam superheater tubes D which extend between the tubes C upwardly to intake and outlet transverse headers D and D2. Above the axis of the liberating drum B, and to the rear thereof I place a steam and feedwater receiving drum E, which is connected by a bank of steam conveying tubes E which enter the shells of said drums at the upper portions thereof, the said drum E being connected to the intake header D of the superheating tubes D by a steam main E2. Within the drum E. l secure a longitudinal division plate e which extends upwardly toward the axis thereof. From the left hand side of said division plate f a bank ol down-flow feedwater tubes l*` connect. said drum E with a Behind the bank of down-flow feed-water i tubes F, I place a series of feed-water preheating up and down How tubes, which may be varranged in any desired manner, but I prefer to provide a series of lower transverse headers G and a series of upper transverse headers G, said headers being connected by alternate up and down-How feed-water tubes G2, the first and second pairs of upper head-v ers G being connected by nipples g, and the second and third pairs of lower headers Gr being connected by nipples g. G3 indicates a feed-water supply pipe leading from a `feed-water pump, not shown, to the first lower transverse header, and from the last upper transverse header a feed-water pipe G4 connects with the pipe G5 in the drum E which conducts the feed-water to the left hand side of the division wall e therein. A blow off pipe a is connected with the muddruin A, and another blow-olf pipe f is connected with the header-drum F', by means of which said drums can be relieved of any sediment which may accumulate in said drums. H and`H indicate pipes by means of which the water column H2 and sight glass, of usual construction is connected with the liberating drum B, which indicates the elevation ofthe water level, as shown by broken line J, in the liberating drum B.

In front of the mud-drum A is a rear fire wall K, from which grate-bars K extend to the boiler setting said fire wallK engages the rear side of the drum l.4` thereby sealing the same from the passage of fire gas therebetween. The rear wall M is provided with a chamber for the lreception of the lower headers G, which is provided with a cover M. The rear wall M is also provided with -a flue opening M2 with which the chimney,

not shown, is connected. N indicates the roof or cover which extends from the rear wall M to the front wall L, enclosing the furnace space of' the boiler setting.

In operation the drums and connecting water tubes are filled with water until the waterlevel in the drums B and E corresponds to the broken line .l as shown by the water column glass, the water covering the the ser1es of pre-heating tubes G2 will be,

enough lower in temperature than the fire gas in that portion of the boiler setting immediately preceding the flue opening M2 to ensure a sucient transference of heat to the feed-water in said tubes, to pre-heat the same prior to its introduction into the drum E at the left hand of the division plate e, that it will be raised to substantially the boiling point after it has traversed thc down and u -flow banks of tubes F and F2, and is trans erred thereby to the right hand side of saidA division plate e, from whence it ows downwardly through the bank of feedwater tubes F3 into the drum A, from whence it continually circulates through the 11p-flow tubes C, drum B, down flow tubes C and drum A, liberating steam therefrom in the drum B, which flows therefrom through the bank of steam tubes E immediately under the cover N of the setting, into the drum E from whence it is conducted through the steam main E2 to the intake header D of the superheater tubes D, wherein the surplus moisture in the steam is -baked out, and enters the discharge header D2 thoroughly dried out and ready for use. It will be observed that the water .tubes containing the coldest water are located in that portion of the boiler setting wherein a large part of the heat units are the least having been gradually absorbe-d by the preceding banks of water tubes, and that proceeding forward toward the source of heat the banks of tubes successively contain water of higher temperature. It will also be observed that with my improved construction, baille walls to form return bend passes are eliminated,-

thus providing a direct course for the fire gas to the fiue opening, rendering tall chimneys or forced draft unnecessary, the successive banks of tubes arranged transversely of the course of the fire gas supplying all the resistance thereto necessary for an efficient transference of heat to the Water contained in the tubes, the said tubes successively reducing the temperaturc'of the fire gas so that when it enters the flue opening M2 there will only be sufficient heat remaining therein to give the necessary draft for the furnace.

The feed water passing through the preand C will remain clean and perform their function efficiently.

rI`he superheater tubes being installed ,behind the bank of uptlow tubes C, are somewhat shielded from the furnace tire, and aid in absorbing heat from the fire gas so that the bank of downflow water tubes C are in a zone of lower temperature, with relation to the up-iow tubes C, thus facili tating the down-flow of water therein, whereby the speed of circulation in said banks of tubes is increased. Likewise the bank of up-flow feed-water tubes F2 being nearer the source of heat will be hotter than the bank of down-flow water tubes F thus facilitating the flow of feed-water therethrough.

The drum `E from which steam is taken for use, when excessive demand is made thereon, has the pressure therein reduced appreciably below the pressure of steam in the liberating drum B, which difference in pressure is partially overcome by placingthe drum E above the axis of the drum B 't so that the feed-water in the bank of tubes F8 will not be caused to back up by the steam pressure in the liberating drum B, whereby a continuous How of feed-water into the evaporating portion of the boiler is maintained.

I-Iaving thus fully shown and described my invention so that others can utilize the same I do not desire to be limited to the exact construction shown and described, as I am aware that many modifications can be made therein without departing from the scope of my invention, but what I claim as new and desire to secure by Letters Patent 1s:

l. In a steam generator of the class described, front and rear walls, a rear fire wall intermediate of said front and rear walls, a roof .extending over thespace between said front and rear walls, a smoke flue opening at the upper rear corner of the space enclosed by saidwalls, a mud drum contacting with the upper portion of said fire wall, an upper steam liberating drum adjacent to the front upper corner of the space enclosed by said walls and roof, a-

tubes connecting the upper. portions of said drums, a lower header drum, down and uplow water tubes connecting said steamf andfeed-water receiving drum and said header drum, a vertical division wall in said steam and feed-Water receiving drum between the upper ends of said banks of down and uplow feed water heating tubes, a bank of down flow feed Water tubes connecting said feed-Water and steam receiving drum with said mud drum, and a series of feed-water pre-heating tubes adjacent 4to the smoke flue opening, all of said banks of tubes being inclined at substantially the saine angle, and parallel with each other, and arranged transversely to the passage of re gas toward the smoke flue.

2. In a steam generator of the class described, a mud drum, an upper steam liberating drum, an inclined bank of up-lw water tubes connecting said drums, an inclined bank of down-flow water tubes spaced from and behind said up-flow tubes connecting said drums, steam superheater tubes between said banks of Water tubes, a feed- Water and steam receiving drum above the axis of said liberating drum, a bank of steam conveying tubes connecting the upper portion of said liberating and feed-water and steam receiving drums, a bank of feedwater tubes connecting said feed-water drum and Said mud'drum, a lower header drum, banks of down-flow and 11p-flow water tubes, connecting said header drum with said feed Water drum, a vertical division plate in said feed-water drum between the upper ends of said banks of tubes, a 'series of feed-Water pre-heating tubes behind'said last mentioned banks of down and up-flow water tubes, and means to conduct feed-water from said preheating tubes into said feed-water drum at the rear side of said division plate. l

In testimony whereof I atlix my signature.

LAWRENCE n. coNNELLY. 

